The present invention relates to devices for connecting electrical tubing or conduit to electrical panels or junction boxes and specifically to a device that is liquid-tight, adaptable for snap-in or threaded connection to a panel, and easier to use than current connectors that are commonly used in the trade.
Liquid-tight connectors are commonly used in the electrical industry for providing a liquid-tight connection between electrical conduit and panels or junction boxes. These connectors are usually multi-piece devices in which a portion must be dismantled to fit the conduit into the fitting and then reassembled to secure the conduit. Most of these prior art fittings require the use of a hand tool to tighten a nut sufficiently to achieve a liquid-tight connection between the conduit and the connector. Most prior art liquid-tight connectors also require the tightening of a nut on the leading end of the fitting to achieve a liquid-tight connection between the fitting and the panel or junction box.
For example, U.S. Pat. No. 4,900,068 to Law, granted Feb. 13, 1990 (hereinafter the ""068 patent) claims a liquid-tight connector that accepts a non-metallic conduit that is grasped by fingers on a clip grasping above an annular ring on a ferrule. To fit the conduit into the liquid-tight connector of the ""068 patent, the installer must insert the conduit into the fitting, and then tighten a compression nut with a hand tool such as a wrench to close the fingers on the clip and thereby achieve a liquid-tight fit. The leading end of the fitting is threaded and must be inserted into the knock-out of a panel or box, a nut is screwed onto the threaded end, and then a hand tool is typically used to secure the fitting to the panel or box. A hand tool therefore is typically employed to achieve a secure liquid-tight fit on both the trailing end of the fitting, between the conduit and the fitting, and on the leading end of the fitting, between the fitting and the panel or box.
U.S. Pat. No. 5,072,072 granted to Bawa, et al., on Dec. 10, 1991 (hereinafter the ""072 patent) attempts to improve upon the fitting provided in the ""068 patent by providing a fitting that requires minimal torque on a gland nut to secure the conduit to the trailing end of the fitting. The gland nut must be removed from the connector body and then is inserted over an electrical conduit with the outer surface of the conduit being received through the centrally located bore of the gland nut. The conduit is then pushed onto a ferrule. Upon tightening of the gland nut on the connector body claimed by the ""072 patent, the gland nut engages resilient fingers with minimal friction loss, thereby enhancing hand tightening or minimizing the torque required with a tightening tool. The ""072 patent therefore requires the separate operation of tightening a nut either by hand or with a tightening tool. The leading end of the fitting in the ""072 patent is typically threaded and requires the use of a nut and an O-ring to secure the fitting to the panel and achieve a liquid-tight fit.
Therefore, as described above, the disadvantages of existing art liquid-tight connectors for connecting conduit to panels include:
(a) The connector includes from two to five separate pieces, some of which must be partially or completely disassembled at the jobsite prior to insertion of the conduit and then reassembled after the conduit is inserted into the trailing end.
(b) Prior art liquid-tight connectors for conduit typically includes a compression, gland, or other nut that must be tightened by hand or by a tightening tool to achieve a liquid-tight connection on the trailing end between the conduit and the connector.
(c) The leading end of prior art liquid-tight connectors for electrical conduit typically require the use of a nut that must be tightened with a hand tool to achieve a liquid-tight fit between the connector and the panel.
(d) A separate sealing ring or O-ring is typically provided with prior art liquid-tight conduit connectors and must be assembled onto the leading end of the connector prior to insertion of the leading end into the knock-out on a panel or box.
The present invention combines the advantages of the improved liquid-tight connector of U.S. patent application Ser. No. 10/017,537, filed Oct. 22, 2001 with the advantages of the threaded snap in connector of U.S. patent application Ser. No. 10/034,156, filed Dec. 26, 2001. Both of these references are incorporated herein by reference. U.S. Pat. Ser. No. 10/017,537 provided a liquid-tight connector assembly that may be simply installed by pushing a conduit into a channel on the trailing end of the connector and then pushing the leading end of the connector into a knock-out in a panel until outward projecting tangs on an annular steel spring adapter snap into place and create a liquid-tight fit. The steel spring adapter required that the leading end of the connector be threaded. U.S. Pat. Ser. No. 10/034,156 provided an improved connector with a threaded leading end and an improved snap ring that could be fitted on the leading end of the connector to provide a quick snap-tight connection to a knockout in a panel or could be removed to allow the connector to be screwed into a threaded access hole in a panel. The present invention therefore combines the versatility of the improved snap ring with the easy-insertion liquid-tight connector.
The present invention is an assembly of parts that is provided as a one-piece connector for achieving a liquid-tight seal between a non-metallic or metallic conduit and an electrical panel or box. The connector includes a tubular body with an axial bore there through and a centrally located flange dividing it into two ends including a leading end having threads on its exterior surface and a trailing end having an extending ferrule. A snap ring and a sealing ring are included on the leading end. Inward facing tabs on the leading end of the snap ring fit into a depression of the leading end of the connector thereby securing the snap ring to the connector. The trailing end of the connector accommodates a tubular retainer body and a tubular retainer body cover. The connector is an assembly of the separate pieces, none of which need to be disassembled when placed in use. The retainer body is held around the ferrule or trailing end by the retainer body cover that is screwed onto a threaded shoulder extending from the central flange. The sealing ring is held on the leading end of the connector by outward projecting grounding tangs on the snap ring. The connector assembly has the advantages of providing a one-piece connector assembly which may be simply installed by pushing a conduit into a channel on the trailing end of the connector and then pushing the leading end of the connector into a knock-out in a panel or junction box until the outward projecting tangs on the steel adapter snap into place to engage the wall of the panel or box. The connector therefore is a significant labor saving device over prior art liquid-tight conduit connectors as disassembly of parts is not required and hand or tool tightening of nuts is not required on either the leading or trailing end. If it is desired to connect a conduit to a panel through a threaded access hole, the snap ring may be easily removed and the connector may be secured by screwing the leading end into the threaded hole.